Magnetic core structure



NOV. 12; 1963 w, FLDQWDLE ETAL 3,110,874

MAGNETIC CORE STRUCTURE Filed Jan. 24, 1961 2 Sheets-Sheet 1 INVENTORS; W191! E BUM/0Z5, us/1 men/5,

BYL-J7Wm ATTORNEY.

Nov. 12, 1963 w. F. DowDLE ETA].- 3,110,874

MAGNETIC CORE STRUCTURE Filed Jan. 24. 1961 2 Sheets-Sheet 2 INVENTORSI:

W/MTE/P [OOH 0A5, HUGH KH/VE,

BY fww ATTORNEY.

United States Patent 3,110,874 MAGNETIC CORE STRUCTURE 7 Walter F. Dowdle, Lincoln, and Hugh Kane, Normal, IIL,

assignors to General Electric Company, a corporation of New York Filed Jan. 24, 1961, Ser. No. 84,571 8 Claims. (Cl. 336-210) and frame in order to compress the laminations and effeotively dampen vibrations of the laminations and accompanying noise. However, the use of such fasteners produces a number of detrimental results. .One of the 7 worst of these is magnetic loss, due to rivet or bolt holes in the 'laminations, which reduce the eifective magnetic strength of the structure. In addition, riveting of the laminations to a frame produces mechanical stresses which must be relieved by'a heatatreatin-g operation. Another undesirable condition, arising from the use of rivets,

is that the intenlamination resistance may remain rel-atively high even though vibrationmay be dampened.

A principle object of the present invention is to provide an improved magnetic core structure for electromagnetic devices.

Another object of the invention is to provide an improved laminar core structure for an electromagnetic device. I Yet another important object of the present invention is to provide an electromagnetic laminar core structure having improved means for uniting the plurality of core laminations into a unitary core structure.

A further object of this invention is to provide a new and improved laminated magnetic structure in which the noise and vibration of magnetic forces is reduced.

Another object is to provide an efiicient magnetic core structure of simple and rigid mechanical design, with greatly reduced power losses.

A feature of the electromagnetic device of this invention is the provision of an electromagnetic core structure and supporting frame therefor having a resilient means to compress the laminations of the core by interaction of the resilient means between the laminations and its supporting frame. With such an arrangement, a retaining means is provided to secure the supporting frame to the electromagnetic core structure in a manner that does not require holes in the laminations and thereby reduces magnetic losses. Also, in magnetic structures in which shading coils are to be used, the shading coils may be retained on the core structure by the aforesaid resilient means for engaging and compressing the laminations of the core. I

While the specification concludes with claims particular-1y pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed the invention will be better understood from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view of the assembled magnetic core structure of the invention;

FIGURE 2 is an exploded perspective of FIGURE 1 7 ice FIGURE 4 is a vertical sectional view takenalong 4-4 of FIGURE 1; and

FIGURE 5 is a perspective view of a core lamination in accordance with the invention.

Referring to the drawings and more particularly to FIGURES 1, 2, 4 and 5, it will be seen that the device of the subject invention comprises a frame or support 16, IFIGURE 1, which may be of die cast construction and is employed as a mounting base or nest for a laminar magnetic core generally shown at 11. The laminar core 11 consists of a stack of a plurality of laminations such as the single lamination shown in detail by 12,

FIGURE 5. The die cast frame 10 is provided with a channel 13 within which the magnetic core 11 of stacked laminations is retained. In order to compress the stack of laminations forming the core 11 within the channei 13, resilient members 14 and 15, as seen in the disassembled exploded view of FIGURE 2, are provided to interact with the inner walls of channel 13 and the core 11.

The resilient members 14 and 15 are general-ly of leaf spring construction as shown'in FIGURE 2. When desired, shading coils may be placed on the core :11 in order to improve its magnetic characteristics. The shading coils, such as shown at 1-6 and 17, may be placed in grooves 19 and 20, 21 and 2.2 that are formed on the upper and outer faces of the core 11, by the notches 24 and 25, 23 and 26 on the upper and outer edges of each individual lamination v12, FIGURE 5. The aforementioned leaf springs 14 and '15, which primarily function to compress the core laminations, may be received under the respective shading coils 16, '17 at 16a and 17a to additionally function to retain the shading coils in place. When the laminar magnetic core 11 is compressed within. the frame 1, FIGURE 1, the leaf springs 14 and 15 will react under compression to engage and retain the shading coils at 16a and 17a respectively, on the core 11. These leaf springs 14 and 15 also serve to take up variations in lamination thickness.

Each individual lamination 12 may be provided with notches 4-2 and 43 preferably of semicircular cross section to receive retainer means 44 and 45 which hold the laminar magnetic core 11 within the frame 10 as shown in FIGURE 4. FIGURE 5 shows a preferred form of lamination with semi-circular notches 42-and 43. In the embodiment illustrated in FIGURE 4 the retainer means 44 and 45 are roll pins which engage the grooves 46, 47 in the outer face of the stack of laminations forming the magnetic core '11, which grooves are formed by the aforementioned semicircular notches 4'2 and 43: in the outer edges of the individual lamination 12. However, any other suitable form of retainer means may be employed. It will be noted that in the FIG- URE 4 modification the frame 10 is also provided with semi-circular grooves 48, 49 so that the respective roll pins 44, 45 will retain the assembly of the core within the frame. The roll pin-s do not actually pass through holes in the laminations as is the case with conventional riveted or roll pin structures.

. FIGURE 3 shows one useful application of the core structure of the subject invention, as part of a contactor shown, generally at 51. An armature 52 is normally held in a raised condition by the action of springs, not shown, when the contactor 51 is de-energized. Upon energization of the contactor 51, the laminar magnetic core structure will. attract the armature 52 causing actuation of contacts generally shown at 53, 54, '55 and 56. The core 11 is assembled in the frame 10 in the manner described above, according to the invention.

Although a particular embodiment of the subject invention has been described, many modifications may be made, and it is understood to be the intention of the r 3 appended claims to cover all such modifications that fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States iszvi l. A magnetic struciture'comprising a frame having inner walls defining a channel, a core comprising a plurality of laminations of magnetic material positioned in said channel, and resilient means independent of said frame engaging an inner wall of said frame and said laminations to compress said laminations.

2. A magnetic structure comprising a frame having inner walls defining a channel, a core comprising a plurality of laminations of magnetic material positioned in said channel, a shading coil on said core, and resilient means independent of said frame engaging an inner wall of said frame and said larninations to compress said laminations, said resilient means also engaging said coil to retain the coil on the core.

3 A magnetic structure comprising a frame having inner walls defining a channel, a core comprising a plurality of laminations of magnetic material positioned in said channel, releasable retainer means engaging said core and said frame to hold said laminations within said channel, and resilient means independent of said frame engaging an inner wall of said frame and said laminations to compress said laminations.

4. A magnetic structure comprising a frame having inner walls defining a channel, a core comprising a plurality of laminations of magnetic material positioned in said channel, releasable retainer means engaging said core and said frame to hold said laminationswith-in said channel, a shading coil on said core, and resilient means independent of said frame engaging an inner wall of said frame and said laminations, said resilient means also engaging said coil to retain the coil on the core.

5. A magnetic structure comprising a frame having spaced opposed inner walls defining a channel therebetween, a core comprising a stack of laminations of magnetic material positioned in said channel, an inner wall of said frame having a groove, each of said laminations having a notch in its outer edge to form a groove extending along the outer face of the stacked laminations; said groove in the stack of'ilaminations being positioned opposite the groove on the inner wall of said frame, and roll pin retainer means positioned within the grooves in the stack of laminations and the frame, thereby holding said laminations within said channel.

6. A magnetic structure comprising a frame having a pair of spaced opposed inner end walls and having a pair of spaced opposed inner side Walls adjacent the end Walls to define therebetween a channel, a core comprising a stack of magnetic laminations positioned within the channel, said core having opposed end faces and opposed side faces adjacent respectively the end walls and the side Walls of said frame, a shading coil on said core, and resilient means independent of said frame engaging a side wall of the frame and a side face of said core and having a part extending through the shading coil to compress the laminations and to retain the shading coil on the core.

7. A magnetic structure comprising a frame having a pair of spaced opposed inner end walls and having a pair of spaced opposed inner side Walls adjacent the end walls to define therebetween a channel, a core comprising a stack of magnetic laminations positioned within the channel, said core having opposed end faces and opposed side faces adjacent respectively the end walls and the side walls of said frame, a shading coil on said cone, resilient means independent of said frame engagsaid frame and said core, and a pin extending through said composite opening to retain said core within said channel.

8. A magnetic structure comprising a frame having a pair of spaced opposed inner end Walls and having a pair of spaced opposed short side walls adjacent each of said end walls to define therebetween a substantially opensided channel, a core comprising a stack of'magnetic laminations positioned within said channel, said core hav ing opposed end faces and opposed side faces adjacent respectively the inner end walls and the short side walls of the frame, a pair of shading coils on said core, and a pair of leaf springs each engaging one side wall of a separate pair of side walls and a side face of said core, said leaf springs having terminal parts extending through said shading coils to retain the shading coils on said core.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A MAGNETIC STRUCTURE COMPRISING A FRAME HAVING INNER WALLS DEFINING A CHANNEL, A CORE COMPRISING A PLURALITY OF LAMINATIONS OF MAGNETIC MATERIAL POSITIONED IN SAID CHANNEL, AND RESILIENT MEANS INDEPENDENT OF SAID FRAME ENGAGING AN INNER WALL OF SAID FRAME AND SAID LAMINATIONS TO COMPRESS SAID LAMINATIONS. 